On Wed, 2011-10-19 at 14:42 -0500, Pat Hayes wrote:
> On Oct 19, 2011, at 10:28 AM, Sandro Hawke wrote:
>
> > On Wed, 2011-10-19 at 13:32 +0100, Andy Seaborne wrote:
> >>
> >>>>> (1) try to model without using either one, when feasible
> >>
> >> which I took as also pushing RDF lists into the "not preferred
> >> category". That's seems to be letting the technology influence the
> >> modelling too much.
> >>
> >> The fact that an ordering construct is an RDF list which "has issues"
> >> isn't the fault of the modeller.
> >
> > Right... What I was trying to get at here was the advice I often hear
> > that modelers should not be using this kind of construct at all.
>
> Who is giving that advice? And what reasons do they give? OWL uses the vocabulary, so I dont think we should be giving advice which suggests that OWL/RDF is broken or deprecated.
>
> >
> > Honestly, I'm very confused about this bit. Perhaps it's best addressed
> > by having a little bit in the tutorial showing how something can be
> > modeled with lists or without lists, and explaining the tradeoffs.
>
> Im not aware of how to model something that needs lists without using lists. Can you give more details?
Mostly I'm thinking of something Bijan said, some years back, although
it's been mentioned in recent meetings, too. It's not about modeling
something that needs lists without lists; it's about modeling things
that *don't* need lists using lists.
That is, Bijan was saying that he's often seen people use lists when
they don't need to. A list of children, from oldest to youngest. A
list of employees of a company. A list of offices, in room-number
order.
So the point is that folks should consider whether lists are really the
best tool. If they are, then certainly use them. But if the order is
in the data already, or something, then don't use a list.
In that same discussion, he said I shouldn't be using lists to say "and
no more", but should instead be giving cardinality. That is, if Alice
wants to say she has two children (Bob and Charlie) and ONLY those two
children, I could use a list:
:Alice :children ( :Bob :Charlie ).
but Bijan strongly advocated:
:Alice :child :Bob, :Charlie
and some bit of OWL by which I say Alice has two children. It's not
clear to me what's best for this.
(I'm also fine with the RDF WG staying out of this modeling topic
entirely.)
-- Sandro